Plot hole: The Jupiter 2 crew is duplicated; however, the aliens had never seen Penny (or Judy I think). How can they be duplicated? The aliens don't have ability to know who were there, or they wouldn't have questioned Smith about the crew. Also, they do not know Smith and Will are hiding. So, they don't arm to have any special power to know beyond what they actually observe.
Happy Birthday... Everybody - S3-E20
Plot hole: After a chance meeting in Mexico, Tom Matthews invites Kelly and Scott to his home for dinner. The address is unlisted, neither knows where the other lives or is staying, and no address or phone information is exchanged before they part. But Kelly and Scott somehow find the house anyway. (00:09:50)